Glass panels are widely used as doors and partitions in a variety of commercial and business settings. A popular way of mounting glass panels as doors or partitions employs support rails or similar frame elements which attach to only the top and bottom edges of the glass panel. This method eliminates the need for vertical side frame elements and thus permits an unobstructed view through a series of contiguous glass panels. Individual support rails are assembled onto the top and bottom extremes of the glass panels and allow the panels to be mounted to either the floor and ceiling if the panel is to be used as a partition or wall, or appropriate door frame means if the glass panel is to be used as a door.
The assembly of the support rail with the glass panel is traditionally performed by the glass temperer or glazier Previously, this assembly was accomplished using a "wet glazing" method, wherein the edge of the glass panel is placed in a U-shaped channel in the support rail and the remainder of the channel is filled with cement This process is necessarily difficult, time consuming and somewhat permanent. Recent developments in support rails have allowed for a "dry glazing" process, whereby the glass panel is secured to the support rail mechanically, using screws or similar clamping means. While these newer support rails can be adjusted and removed prior to and even after final assembly, the clamping mechanisms are relatively involved and the support rails accordingly difficult and time consuming to assemble. In addition, many support rails are designed to accommodate a single mounting arrangement. Since different installation specifications may require variations in the placement of the mounting elements, for example, the door closure means, the pivot element and the lock assembly, these existing support rails may be unusable in certain installations. Therefore, it is desirable to provide a support rail which is versatile enough to be used in a wide variety of installations. It is also desirable to provide such a support rail that is simple and quick to assemble.
An existing support rail device is shown in U.S. Pat. No. 4,655,025 to Marinoni, which discloses an edge rail for of differing lengths which must be interconnected by way of a flanged lock. Each of these rail sections, in turn, is comprised of two rail members which are attached to one another by way of transverse screws and which define two clamping jaws between which the glass panel is held when the transverse screws are tightened. Marinoni's rail further comprises two cover strips or side shrouds which, due to the placement of the transverse screws, can only be attached after the rail members are assembled with and clamped to the glass panel. Moreover, future maintenance of the support rail requiring access to the transverse screws would require detachment of the cover strips from the rail members.
Another prior art support rail device is disclosed in U.S. Pat. No. 4,680,903 to Horgan, Jr., which shows a metal frame for a glass door comprising a longitudinally extending shoe member having an H-shaped cross section forming an upper channel into which the edge of a glass panel is received, a strip of double-faced tape along one side surface of the upper channel, and a number of pressure units in spaced apart relation to one another along the other side surface of the upper channel for securing the glass panel within the channel of the door shoe. Thus during assembly, the pressure units must be positioned within the channel of the shoe member and loosely held in place while the glass panel is aligned within the channel and squared with the shoe member. Then the glass panel must be removed so that the protective cover of the double-faced tape can be removed. Finally, the glass panel must be replaced and the screws within the pressure units advanced to secure the glass panel within the channel. The pressure units, moreover, only engage the glass panel at discrete locations along the length of the shoe member.
Existing support rails are commonly made of metal, which increases the weight of these rails and requires sturdier frame members to accommodate the glass panel and support rail assembly. Moreover, attempts to reduce the amount of metal used have resulted in support rail elements having complicated exterior side profiles which make the manufacture of the support rail and attachment of side shrouds difficult and involved. In addition, slight variations in the thickness of a panel of glass can create difficulty in clamping the support rail to the glass and cause stress points to exist in the glass once it is clamped within the rail. Furthermore, repeated use of a glass door comprised of a rail support and a glass panel may result in the glass panel dislodging from the rail support.